The present disclosure relates to a rotating device and an image forming apparatus including the same.
In general, an electrophotographic image forming apparatus includes a fixing device. The fixing device heats a toner image formed on a sheet so as to fix the toner image to the sheet. The fixing device includes a heater and a heating roller that is heated by the heater.
For example, the fixing device may further include a fixing roller, a pressure roller, and an endless fixing belt, wherein the fixing roller and the pressure roller rotate while nipping the sheet. In this case, the fixing belt is stretched over the heating roller and one of the fixing roller and the pressure roller in a state where a tensile force is applied to the fixing belt. The fixing belt applies a pressure to the heating roller.
The heating roller may include a roller main body and a resin member that is attached to an end portion of the roller main body. The roller main body is a metal-made cylindrical body formed in a cylindrical shape. The resin member rotates integrally with the roller main body. For example, the resin member is a gear that transmits a rotational force to the roller main body, or a bush that supports the roller main body.
It is noted that the fixing device is an example of a rotating device that includes the metal-made cylindrical body, the resin member attached to an end portion of the cylindrical body, and a member that applies a pressure to the cylindrical body.
The resin member and the roller main body made of metal differ from each other in thermal expansion coefficient. As a result, the fixing device including the heater is apt to generate abnormal noise due to looseness between the resin member and the roller main body.
For example, there is known a technique to prevent generation of the abnormal noise by adjusting a dimensional difference between an outer diameter of the roller main body and an inner diameter of a synthetic-resin-made gear fitted onto an end portion of the roller main body, and adjusting roundness of the gear.